This invention concerns air dispersed oil or dust or other solid or liquid contaminant collectors of a type described and claimed in corresponding U.S. patent application published as 2008/0105129-A1.
That application describes an oil mist collecting system which includes an individual oil mist collector at each station of a series of machine tools and directing the demisted air to a central air filtration unit such that transporting mist laden air over substantial distances is avoided.
The oil mist collectors are of a spiral coil design in which mist laden air is directed in to the space between turns of a spiral wall, with the turns oriented vertically so that condensed oil drains down (along with any chips or fines) into an associated individual mist collection tank which in turn drains into a machine tool sump (or return chute or trench) to be handled by the system cutting fluid filtration apparatus, eliminating the need for disposal of the collected oil.
The spiral coil is held in a housing assembly which can be installed in line with a mist inlet, air collection ducting and drainage connections with simple inline connections to mist inlet ducts and air outlet ducts as well as to a drain.
The condensed oil is collected in an individual collector tank located immediately below the drain and drainage is controlled by drain valves of a special design which prevent entry of a back flow of air from being drawn in over the collected oil. These valves preferably accommodate any chips or other debris.
The location of the collection chambers immediately below the spiral coil exposes the collected oil and chips to a cyclonic air flow which retards settling out of the chips and drives the oil and chips out to the outer wall where a drain opening is located to receive the collected oil and chips and pass the same to the drain value.
While this type of contaminant removal device has been successful in oil demisting, there has been found a tendency for some oil misting to redevelop in the air flow as a result of contact with oil that has been found to accumulate at the center of the bottom of the collection chamber. It has been found that the condensed oil tends to puddle in the center and erupt into the return air flow which is flowing up to the air outlet. This recreates some oil misting in the outflow air.
The cyclonic flow technology has also been applied to removal of solid air dispersed contaminants such as dust. However, in the past, such dust collectors have been very tall due to the tendency for dust to be drawn back into the outlet air flow if the outlet was too close to the bottom of the collection chamber.
It is an object of the present invention to provide improved performance of the type of air dispersed contaminant removal device described by substantially eliminating the tendency for redevelopment of oil misting in the air flow exiting from the collection chamber.
It is a further object to provide a dust an air dispersed solid or liquid contaminant removal device of the same type which is of shorter height due to performance of the collector.